The risk of stroke and other major cardiovascular events can be reduced in people with high blood pressure or a history of stroke simply by replacing salt with salt substitute.
That was the findings of a major study of more than 20,000 people in China, with researchers saying this simple measure “has the potential to reduce health inequities related to cardiovascular disease”.
While salt substitutes are known to lower blood pressure, the role they play in reducing the risk of stroke, heart disease and even mortality rates had been unclear.
The Salt Substitute and Stroke Study set out to investigate the link and compare the effect of reduced sodium salt substitute compared to normal salt on cardiovascular events and clinical hyperkalaemia. Previously, there had been concerns about the link between salt substitutes and hyperkalaemia in people with chronic kidney disease, leading to cardiac arrhythmias and sudden death.
The trial, which took place from April 2014 to January 2015, involved 20,995 adults across 600 villages in rural China. They either had previous stroke or were aged over 60 with poorly controlled blood pressure.
People in intervention villages were given free salt substitute for use in cooking, seasoning and food preservation. In addition, they were advised to use it more sparingly compared to how much salt they normally used, to further reduce their sodium intake. People in control villages continued to use normal salt.
The key findings were that the risk of stroke and major cardiovascular events was reduced with salt substitute compared to regular salt, and that there was no increased risk of serious events attributed to hyperkalaemia with salt substitute in comparison to regular salt.
Principal investigator Professor Bruce Neal, of the George Institute for Global Health in Sydney, Australia, said: “This study provides clear evidence about an intervention that could be taken up very quickly at very low cost. A recent modelling study done for China projected that 365,000 strokes and 461,000 premature deaths could be avoided each year in China if salt substitute was proved to be effective. We have now showed that it is effective, and these are the benefits for China alone. Salt substitution could be used by billions more with even greater benefits.
“Importantly, salt substitute is very easy to manufacture and it is not expensive. It is primarily lower-income and more disadvantaged populations that add large amounts of salt during food preparation and cooking. This means that salt substitute has the potential to reduce health inequities related to cardiovascular disease.”
The study has been published in the New England Journal of Medicine.
